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<p><b><font size=+1>SoftImage Tips and Tricks</font></b>
<p><font size=-1>gregw@wdi.disney.com</font>
<br><font size=-1>updated 2/26/2002</font></center>

<p><br>
<br>
<br>
<br>
<p>The following document contains certain advice for getting models and
animations through the
<br>soft2egg converter in one piece.&nbsp; Some of these restraints are
due to differences between Panda
<br>and SoftImage and some are workarounds for SoftImage&nbsp; idiosyncrasies.&nbsp;
The first section is advice
<br>for set-up, modelling, and animation. The second section describes
some frequently seen problems
<br>after conversion attempts. If you have any questions please don't hesitate
to ask.
<br>&nbsp;
<br>&nbsp;
<p><b><u>Section I&nbsp; - Set-up</u></b>
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Hierarchy naming:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; The converter needs to ignore
most of the constraint hierarchies and they are not always
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; flagged invisible so the
code will ignore any nodes (and anything below them) with the
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; following strings in their
names:
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
con-
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
con_
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
fing-
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
eyes-
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
faces-
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
head-
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
camRIG
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
bars
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If you don't do this, the
converter will make geometry for the sliders and the camera. I freely
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; admit there is some kruft
in this keyword list.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Model naming:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Try to make the models have
consistent names through the revision process. SoftImage is
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; terrible about appending
version numbers onto everything in the scene file (null12_1_1, etc.)
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Each time a model name changes
it's highly likely that a makefile or the show code will break.
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; While it is possible to
"fix" this with wildcards (null12*) it is undesirable as this is no longer
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; unique and can cause other
problems.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>NURBS Textures:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Textures applied to closed
NURBS surfaces in Soft will have problems in Panda. This is because
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Soft uses phantom vertices
in their NURBS representation and this seems to affect where they
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; start and stop applying
the texture. This can be fixed by shifting the NURBS parameterization.
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; You can do this on the surface
in question through the Soft GUI, or you can do for all surfaces
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; in the scene upon conversion
with the "-x" option to soft2egg.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Model scale:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; It seems the general convention
here in the VR Studio has been for the animators to scale the
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; character models up by a
factor of four while animating. I believe this is because Soft has limited
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; precision. Thus models should
be scaled by a factor of one fourth to look right in Panda.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Non-uniform scaling of joints:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; A non-uniform scale is one
that is not the same in all three axes (ie x=1, y=1, z=0.5). If an
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; animation puts a non-uniform
scale on any joint then you must place the key word "scale-" in
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; the name of the joint that
does that scale.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Face shape trickiness:</u>
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Currently SAAPHIRE (the SoftImage
API) is broken when it comes to reading expressions
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; which determine shape weights.
Because of this you MUST put the expressions in strict order
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; of the shape numbers they
affect (ie the expression for shape 0 must be before 1, etc.)
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Animating Nulls:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; When constructing a skeleton
for the player the converter looks at the skeleton nodes in Soft.
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If you are animating a null
directly through some relationship you need to make the converter
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; aware of that by flagging
the null with the prefix "joint-" in its name.&nbsp; Alternatively, you
can
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; do a "GroupAsSkeleton" on
the null in question to make it actually part of the skeleton. It will
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; then have a tiny "Skel"
above the node in the Soft's schematic view.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>The Minus One Frame:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Our animation system works
by computing offsets from a neutral pose in the -1 frame of the
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; scene file. If the character
is not in the "jesus pose" at frame "-1" all bets are off. Animation
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; should not start on anything
in the scene until frame "1".
<br>&nbsp;
<br>&nbsp;
<p><b><u>Section II&nbsp; - Known Pathologies</u></b>
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Part not where it should be:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Frequently Soft does not
update the position of parts that are moved and skinned. It will look
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; right in Soft until you
cut it out of the hierarchy. If the geometry stays where it is after cutting
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; it&nbsp; is fine. If it
pops to a different position it will be problematic. We never did find
a way to make
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Soft update its position
but we did find a fix: do a "duplicate immediate" on the geometry while
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; it is in the correct position;
cut out the old geometry and delete it; skin up the new copy you just
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; made.
<br>&nbsp;
<p>&nbsp;&nbsp;&nbsp; <u>Part stretched out while animating:</u>
<p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; If you put a non-uniform
scale on a joint and don't tag it as described above it will most likely
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; be extremely stretched out
and creepy looking on playback (like Edward Scissorhands). There are
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; other things that can cause
this too (like scaling an egg model and not the egg anim channel and
<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; vice versa). But when in
doubt, throw in the "scale-" flag.
<br>&nbsp;
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